Process

This chapter gives an overview of how Cargo comes together, and how you can be a part of that process.

See the Working on Cargo chapter for an overview of the contribution process.

Please read the guidelines below before working on an issue or new feature.

Mentorship

Some Cargo team members are available to directly mentor contributions to Cargo. See the office hours page for more information.

Roadmap

The Roadmap Project Board is used for tracking major initiatives. This gives an overview of the things the team is interested in and thinking about.

The RFC Project Board is used for tracking RFCs.

Working on issues

Issues labeled with the S-accepted label are typically issues that the Cargo team wants to see addressed. If you are interested in one of those, and it has not already been assigned to someone, leave a comment. See Issue assignment below for assigning yourself.

When possible, the Cargo team will try to also include E-easy, E-medium, or E-hard labels to try to give an estimate of the difficulty involved with the issue.

If there is a specific issue that you are interested in, but it is not marked as S-accepted, leave a comment on the issue. If a Cargo team member has the time to help out, they will respond to help with the next steps.

Working on small features

Small feature requests are typically managed on the issue tracker. Features that the Cargo team have approved will have the S-accepted label.

If there is a feature request that you are interested in, but it is not marked as S-accepted, feel free to leave a comment expressing your interest. If a Cargo team member has the time to help out, they will respond to help with the next steps. Keep in mind that the Cargo team has limited time, and may not be able to help with every feature request. Most of them require some design work, which can be difficult. Check out the design principles chapter for some guidance.

Working on large features

Cargo follows the Rust model of evolution. Major features usually go through an RFC process. Therefore, before opening a feature request issue create a Pre-RFC thread on the internals forum to get preliminary feedback.

Implementing a feature as a custom subcommand is encouraged as it helps demonstrate the demand for the functionality and is a great way to deliver a working solution faster as it can iterate outside of Cargo’s release cadence.

See the unstable chapter for how new major features are typically implemented.

Bots and infrastructure

The Cargo project uses several bots:

• GitHub Actions are used to automatically run all tests for each PR.
• triagebot automatically assigns reviewers for PRs, see PR Assignment for how to configure.
• bors is used to merge PRs. See The merging process.
• triagebot is used for assigning issues to non-members, see Issue assignment.
• rfcbot is used for making asynchronous decisions by team members.

Issue assignment

Normally, if you plan to work on an issue that has been marked with the S-accepted label, it is sufficient just to leave a comment that you are working on it. We also have a bot that allows you to formally claim an issue by entering the text @rustbot claim in a comment. See the Issue Assignment docs on how this works.